System of distribution.



SYSTEM OF DISTRIBUTION.

APPLIGATION FILED DBO. 21, 1910.

Fig. '1.

E. H. SGHWARZ.

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'Patnfiedhec. 30, 1913. v E'LgZ. 4 4' WITNESSES: I

X X X X X X X X X g Y INVENTOR 4M 1 W ATTbRNEY UNITED STATES PATENT OFFICE.

ELMER H. SCHWARZ, NEW YORK, N. Y., ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SYSTEM OF DISTRIBUTION.

Specification of Letters Patent.

Application filed-December 21, 1910. Serial No. 598,523.

Patented Dec. 30, 1913.

I Systems o f'Distributiomof which the fol lowing is a specification.

My invention relates to systems of elec: trical distribution and particularly to constant alternating current lighting systems.

The object of my invention is to provide a polyphase constant alternating current distribution or lighting system which shall have a low initial cost for installation and -in which the electrical losses .due to resist- Heretofore in systems in which translating devices, such as arc lamps, have been in series relation, it has been customary to place the'lamps in separate single-phase circuits having no interconnection and distinct from eachother so that return conductors have been necessary for each circuit. The present system is distinguished from such old systems in the manner set forth.

Figure .1 .ofthe accompanying drawings "is a'diagrammatic view of a system embodying one form' ofi my finvention, and

Figs. 2, 3 and 4 are similarwiews of modifications of the system of Fig. 1.

In the system of Fig. 1, the primary coils 1, 2 and 3 of a three-phase constant-current e regulating device are connected, in any desired relation to each othe to a three-phase 5 supply circuit 45--6, the core 7 of said device com rising three vertical legs that are joined y a yoke and are respectively surrounded by the said coils. As here shown, the rimary coils of the regulator are independently movable with respect to eaoh other, and also with respectto secondary coils 8, 9 and 10, though, if desired, the secondary coils may be made independently movable while the primary coils are retained in a stationary position. The movable coils ave I areindependently counterbalanced by conven1ent means such as weights, as shown in the drawing. The terminals of the secondary coils 8, 9 and 10-are respectively connected to distributing circuit conductors 11, 12 and'13 corresponding to the different phases of'the system, and the remaining terminals 0f the secondary coils'are connected together. Lamps 14, or other translating devices of any suitable character, are connected in series relation in the circuits of each of the conductors 11, 12 and 13, and the said conductors are connected together at points beyond the translating devices. The connected terminals of the coils 8, 9 and 10 and the remote ends of the conductors 11, 12 and 13 are shown connected to the ground, though such grounded. connections may be omitted, if desired.

Since the several phase conductors of the distributing circuit are connected together at their ends remote from the constant current regulator and beyondthe translating devices, no return conductors in addition to those illustrated are necessary, and, consequently, there is a great saving of the material composing the conductors over what would be necessary if the several phases of the system were independent and unconnected. Also, the electrical losses in the system which are due to resistance are, accordingly, materially less than in systems in which the phases are entirely separate. If one phase of the present system becomes disabled,.the remaining phases will still continue to operate and the regulator will maintain constantcurrents therein, since the movable coils thereof are independently movable. For this reason, also, the current in each phase is independently regulated and is maintained constant, -irrespective of the conditions affecting the other phases.

The present system may be employed with advantage under several different kinds of practical conditions. For instance, consider the street; lighting of a comparatively small community .requiring only about as many lamps as are ordinarily placed in one single 4 phase circuit. By using the present system,

the phases of the supplying generator may be kept in balance, only one-third of the total number of lamps are rendered useless in case one phase of the circuit is disabled, and, if the neutral points are grounded. the

voltage strain is only one-third of that in a single phase system, while the maximum voltage between any two conductors of the system is or about of that in a single phase system.

In systems having more than enough lamps for one single phase circuit, a material saving in the cost of conductors. and in resistance losses may be effected by the use of the present system, particularly when the community to be lighted is at some distance from the generating or sub-station.

In Fig. 2, a reactance type of regulator is employed instead of the transformer type shown in Fig. 1, but, in other respects, the character of the system and its mode of operation are the same. In this system, the neutral point of the generator Or intermediate potential transformers supplying the system may be grounded.

In some cases, it may be desirable to employ a plurality of single phase constantcurrent regulating devices, particularly when only one lamp circuitis installed at a time, which may occur in a growing community. A system in which a separate constant-current regulating device of the transformer type is employed in each phaseis shown in Fig. 3, and, in Fig. 4, is shown a similar system in which the regulating device is of the reactance type. In these systems also, the circuits are grounded, in order to reduce the potential strains to values correspondin to those found in a single phase system. 11 each of these systems, the lamp circuits are grounded at their remote or connected ends, and, in Fig. 3, the connected terminals of the secondary windings of the regulating transformers are also grounded. In Fig. 4, the neutral point of the generator or intermediate potential transformers supplying the system is grounded. The

grounded connections may, of course, be

omitted, if'desired. I

I claim as my invention:

1. A system of distribution comprisin a three-phase distribution circuit and a rality of translatin devices connecte in series relation in eac of the phases, and iii-- dependently operative constant-current regulating means for each of the phases.

2. In a system of distribution, the combination with a polyphase constant-current regulator having independently] movable coils for itsrespective phases, of a polyphase distributing circuit leading from the regulator, and series-connected translating devices in each of the phases of the distributing circuit, the conductors of the several phases of the said circuit being connected together at a point beyond the translating devices.

3. In a system of distribution, the combination with a three-phase constant-current regulator having independently movable coils for its respective phases, of a threephase distributing circuit leading from the regulator, and series-connected translating devices in each of the phases of the .distributing circuit, the conductors of the several phases of the said circuit being connected together at a point beyond the translating devices, and the neutral points of or connections between the said phases being grounded.

4. In a system of distribution, the combination with a three-phase constant-current regulator having independently movable coils for its respective hases, of a threephase distributing circuit leadlng from the regulator, and series-connected translating devices in each of the phases of the distributing circuit, the conductors of the several phases of the said circuit being connected together at a point beyond the translating devices.

5. A system of distribution comprising a polyphase distributing circuit, series connected translating devices in each of the phases of the distributing circuit, the conductors of the several phases of the said cir cuit being connected together at a point beyond the translating devices, and independently operative constant current regulating means for each of the phases of the. distributing circuit. 1

Signed at New York, in the county of New York and State of New York this ninth day of December A. D. 1910.

ELMER H. SCHWARZ. 

